* ATLANTIC TC GENESIS INDEX * * GFS VERSION * * AL932021 08/09/21 12 UTC * TIME (hr) 0 6 12 18 24 36 48 60 72 84 96 108 120 Prob of Genesis 30% 39% LAT (deg N) 14.4 14.0 14.0 14.1 14.1 14.0 13.4 12.8 12.6 12.6 13.0 13.4 14.1 LON (deg W) 47.6 48.5 49.2 50.0 51.0 53.3 55.8 58.8 62.0 65.3 68.7 72.1 75.7 DTL (km) 1174 1090 1058 1029 994 906 631 324 212 241 169 107 349 TRACK SOURCE AVNI AVNI TABM TABM TABM TABM TABM TABM TABM TABM TABM TABM TABM TCGI 0-48h Genesis Forecast: 30% is 1.0 times the sample mean ( 30%) TCGI 0-120h Genesis Forecast: 39% is 0.9 times the sample mean ( 43%) --------------------------------------------------------------------------------------------- INDIVIDUAL PREDICTOR CONTRIBUTIONS TO PROBABILITY OF GENESIS ******* 48-HR ****** ******* 120-HR ****** AVG TCGI CONT AVG TCGI CONT DIVERGENCE -1.0 -0.3 5.0% 1.0 -0.1 7.8% VORTICITY 1.7 0.6 3.9% 1.4 0.6 7.3% VERTICAL SHEAR 16.3 6.9 16.1% 18.4 9.3 17.5% RH 73.1 64.6 -0.1% 70.9 59.2 1.3% GOES 29.1 5.7 0.2% 29.3 5.7 0.2% DVORAK 0.8 1.0 5.1% 0.8 1.0 4.8% --------------------------------------------------------------------------------------------- PREDICTOR DEFINITIONS (Averaged Over 500 km Radius) GENESIS CLIM = Climatological Prob (%) of Genesis (Source: NHC-TAFB Invest Database) DIVERGENCE = GFS 850 hPa Horizontal Divergence (x10-7 s-1) VORTICITY = GFS 850 hPa Vorticity (x10-6 s-1) VERTICAL SHEAR = GFS 200-850 hPa Vertical Shear (kt) RH = GFS 600-850 hPa Relative Humidity (%) GOES = GOES Water Vapor Pixels Colder than -40C (%) DVORAK = Dvorak T-number, source: TAFB Version 2.1, February 2018